import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class TcpEchoServer {
    //服务器的端口号
    private ServerSocket serverSocket = null;

    private ExecutorService service = Executors.newCachedThreadPool();

    public TcpEchoServer(int port) throws IOException {
        serverSocket = new ServerSocket(port);
    }

    public void start() throws IOException {
        System.out.println("服务器启动!");
        while(true){
            Socket clientSocket = serverSocket.accept();
//            Thread t = new Thread(() -> {
//                processConnection(clientSocket);
//            });
//            t.start();
            service.submit(new Runnable() {
                @Override
                public void run() {
                    processConnection(clientSocket);
                }
            });
        }
    }

    private void processConnection(Socket clientSocket){
       System.out.printf("[%s:%d] 客户端上线了~\n", clientSocket.getInetAddress().toString(), clientSocket.getPort());
       try(InputStream inputStream = clientSocket.getInputStream();
           OutputStream outputStream = clientSocket.getOutputStream()){

           while(true){
               Scanner sc = new Scanner(inputStream);
               if(!sc.hasNext()){
                    System.out.printf("[%s:%d] 客户端下线了~\n", clientSocket.getInetAddress().toString(), clientSocket.getPort());
                    break;
               }
               String request = sc.next();

               String response = process(request);

               PrintWriter writer = new PrintWriter(outputStream);
               writer.println(response);
               writer.flush();

               System.out.printf("[%s:%d] req:%s, resp:%s\n", clientSocket.getInetAddress(), clientSocket.getPort(), request, response);
           }

       } catch (IOException e) {
           e.printStackTrace();
       }
    }

    public String process(String request){
        return request;
    }

    public static void main(String[] args) throws IOException {
        TcpEchoServer server = new TcpEchoServer(8080);
        server.start();
    }
}
